1. Field of the Invention
This invention relates to an iris identification method and apparatus for identifying an individual by using the iris of human or animals, and a data converter for coding data by using an iris data.
2. Description of the Related Art
There is known an iris identification apparatus for identifying an individual by using an iris of a human. The apparatus gets an image data of iris, produces iris codes from the image data, comparing the produced iris code with registered iris code and identifies the individual.
The apparatus takes photography of an eye with a camera and gets an iris image data. The iris image data is converted into an identification code by predetermined image processing, and the identification code is registered at the apparatus. In the case that an individual recognition is executed, the apparatus acquires an iris image data of the eye through the camera and generate an identification code from the iris image data. The identification code is compared with the registered code in advance. If the identification code agrees with the registered code, the result that the individual recognition completes normality is informed.
The camera provides a lens for taking a photograph of human eye as large as possible. The person""s eye is photographed with the camera while a person to be identified changes a posture so that the person""s eye is placed on an optical axial of the lens.
However, the person has to change briskly the posture until the person""s eye meet the optical axial. Therefore, it is a lot of trouble for the person to be identified.
Furthermore, after the original iris data taken with prescribed posture is registered, it is very difficult to make the same posture in order to acquire an iris data for identifying again. Thus, it is possible that the iris data for identifying disagrees with the original iris data.
However, a problem encountered with the prior art apparatus is that a stable iris data is not taken when a head or face of an identified person is tilting.
Accordingly, it is an object of the present invention to provide an iris identification method and apparatus, which can be obtained a stable iris data even though a head or face of an identified person is tilting.
Another object of the invention is to provide an iris identification method and apparatus, which can identify an iris data accurately even if it can not take photography of a whole iris because an eyelid closes the iris.
Still another object is to provide a data converter for encoding data by using an identification data produced by an iris as a key.
The present invention is an iris identification apparatus for a photographing part for photographing an area including both eyes, a standard line deriving part for calculating a standard line passing through the center of both eyes, an iris extracting part for extracting an iris area on the standard line by luminance distribution, a code producing part for dividing the iris area into a plurality of a piece, calculating a luminance in the plurality of the piece and coding the luminance distribution of the plurality of the piece on the basis of the standard line, a code registering part for registering the identification code, and a comparison part for comparing the identification code produced by the code producing part with the identification code registered by the code registering part.
In another embodiment of the invention, An apparatus for changing data is provided a photographing part for photographing an area including both eyes, a standard line deriving part for calculating a standard line passing through the center of both eyes, an iris extracting part for extracting an iris area on the standard line by luminance distribution, a code producing part for dividing the iris area into a plurality of a piece, calculating a luminance in the plurality of the piece and coding the luminance distribution of the plurality of the piece on the basis of the standard line, and a changing part for changing the data by using the code coded by the code producing part in accordance with the predetermined function.